Fabrication of Cu2O-loaded TiO2 nanotubes with heterojunctions via an electrochemical method: enhanced photocatalytic activity

Modified TiO2 nanotubes (NTs) have been widely used in water splitting for hydrogen evolution owing to their excellent photocatalytic properties. In this study, Cu2O nanoparticle (NP)-decorated TiO2 NTs were fabricated via electrochemical deposition, and the effects of Cu2O NPs on the structure, optical properties, and photocatalytic performance of TiO2 NTs were investigated. The results revealed that the calculated theoretical hydrogen production on the as-prepared Cu2O–TiO2 NTs is 18.19 μmol cm−2 h−1, and the photoelectric conversion efficiency is 22.08%, which is nearly three times higher than that obtained with pristine TiO2 NTs. This indicates that the as-prepared n–n heterojunction Cu2O–TiO2 NTs are an efficient photocatalytic material for water-splitting hydrogen evolution. This study not only provides a facile and tunable Cu-loading method but also an in-depth understanding of the effect of cocatalysts on the photocatalytic hydrogen evolution activity of the primary catalyst.